The present invention relates to a database, and particularly relates to a database management program, a database managing method and a database managing system for carrying out rearrangement of a database or the like on the basis of log information showing access status to data.
As a conventional database optimizing system based on trace information, there is a database optimizing/rearranging system as disclosed in JP-A-5-2515. In this system, information of a method for gaining access to a database at data operation requests issued from respective user programs is accumulated as trace information. When the database is rearranged at regular time intervals, the optimum storage order of data in the database and the necessity of an index are determined with reference to the accumulated trace information. Thus, buffer quantity assignment parameters are created for securing a buffer quantity required for rearranging the database.
In the above-mentioned conventional technique, description is made on a method for optimizing and storing the order of columns, the order of lines and the necessity of creating an index in a database on the basis of access frequency. Such processing is carried out automatically routinely, and information is not disclosed to any user. Therefore, the user does not know what standard is used and what is optimized. Thus, classification between the case to optimize and the case not to optimize about one item cannot be defined by the judgement of the user. In addition, for the optimization of the database, the order of columns or the order of lines is merely changed or creation of an index is merely designated. That is, only static optimization is carried out, and description is not made on any dynamic optimization method in which optimization is carried out in accordance with the behavior of the system always undergoing a variation.
It is an object of the present invention to provide a method and a system for supporting user""s database management to optimize the system dynamically, and a program for carrying out the support.
Further, it is another object of the invention to provide a database optimizing method which can optimize various conditions such as priorities of data, storage places, storage methods, management of resources, indexes, priorities of jobs, and so on, in accordance with optimization rules defined by a user on the basis of a disclosed optimization criterion (reference).
In order to achieve the foregoing objects, database managing means according to one aspect of the invention has a function to extract log information satisfying predetermined conditions from among log information of application programs having accessed to a database, and a function to rearrange data in the database in accordance with predetermined rules on the basis of commands included in the extracted log information.
Other objects, features and advantages of the present invention will become apparent from the description of the embodiments of the invention taken in conjunction with the accompanying drawings.